
<h1><span class="yiyi-st" id="yiyi-13">numpy.ma.MaskedArray.compress</span></h1>
        <blockquote>
        <p>原文：<a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.ma.MaskedArray.compress.html">https://docs.scipy.org/doc/numpy/reference/generated/numpy.ma.MaskedArray.compress.html</a></p>
        <p>译者：<a href="https://github.com/wizardforcel">飞龙</a> <a href="http://usyiyi.cn/">UsyiyiCN</a></p>
        <p>校对：（虚位以待）</p>
        </blockquote>
    
<dl class="method">
<dt id="numpy.ma.MaskedArray.compress"><span class="yiyi-st" id="yiyi-14"> <code class="descclassname">MaskedArray.</code><code class="descname">compress</code><span class="sig-paren">(</span><em>condition</em>, <em>axis=None</em>, <em>out=None</em><span class="sig-paren">)</span><a class="reference external" href="http://github.com/numpy/numpy/blob/v1.11.3/numpy/ma/core.py#L3723-L3789"><span class="viewcode-link">[source]</span></a></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-15">返回<em class="xref py py-obj">a</em>其中条件为<code class="docutils literal"><span class="pre">True</span></code>。</span></p>
<p><span class="yiyi-st" id="yiyi-16">如果条件为<a class="reference internal" href="../maskedarray.baseclass.html#numpy.ma.MaskedArray" title="numpy.ma.MaskedArray"><code class="xref py py-obj docutils literal"><span class="pre">MaskedArray</span></code></a>，则缺失值将被视为<code class="docutils literal"><span class="pre">False</span></code>。</span></p>
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<tr class="field-odd field"><th class="field-name"><span class="yiyi-st" id="yiyi-17">参数：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-18"><strong>condition</strong>：var</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-19">Boolean 1-d数组选择要返回的条目。</span><span class="yiyi-st" id="yiyi-20">如果len（condition）小于沿轴的a的大小，则输出将被截断为条件数组的长度。</span></p>
</div></blockquote>
<p><span class="yiyi-st" id="yiyi-21"><strong>axis</strong>：{None，int}，可选</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-22">必须沿其执行操作的轴。</span></p>
</div></blockquote>
<p><span class="yiyi-st" id="yiyi-23"><strong>out</strong>：{None，ndarray}，可选</span></p>
<blockquote>
<div><p><span class="yiyi-st" id="yiyi-24">用于放置结果的替代输出数组。</span><span class="yiyi-st" id="yiyi-25">它必须具有与预期输出相同的形状，但如果需要，将转换类型。</span></p>
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<tr class="field-even field"><th class="field-name"><span class="yiyi-st" id="yiyi-26">返回：</span></th><td class="field-body"><p class="first"><span class="yiyi-st" id="yiyi-27"><strong>result</strong>：MaskedArray</span></p>
<blockquote class="last">
<div><p><span class="yiyi-st" id="yiyi-28"><a class="reference internal" href="../maskedarray.baseclass.html#numpy.ma.MaskedArray" title="numpy.ma.MaskedArray"><code class="xref py py-class docutils literal"><span class="pre">MaskedArray</span></code></a>对象。</span></p>
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<p class="rubric"><span class="yiyi-st" id="yiyi-29">笔记</span></p>
<p><span class="yiyi-st" id="yiyi-30">请注意与<a class="reference internal" href="numpy.ma.compressed.html#numpy.ma.compressed" title="numpy.ma.compressed"><code class="xref py py-meth docutils literal"><span class="pre">compressed</span></code></a>的区别！</span><span class="yiyi-st" id="yiyi-31"><a class="reference internal" href="#numpy.ma.MaskedArray.compress" title="numpy.ma.MaskedArray.compress"><code class="xref py py-meth docutils literal"><span class="pre">compress</span></code></a>的输出具有掩码，<a class="reference internal" href="numpy.ma.compressed.html#numpy.ma.compressed" title="numpy.ma.compressed"><code class="xref py py-meth docutils literal"><span class="pre">compressed</span></code></a>的输出不是。</span></p>
<p class="rubric"><span class="yiyi-st" id="yiyi-32">例子</span></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">x</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">ma</span><span class="o">.</span><span class="n">array</span><span class="p">([[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">],[</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">6</span><span class="p">],[</span><span class="mi">7</span><span class="p">,</span><span class="mi">8</span><span class="p">,</span><span class="mi">9</span><span class="p">]],</span> <span class="n">mask</span><span class="o">=</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">+</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="mi">0</span><span class="p">]</span><span class="o">*</span><span class="mi">4</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">x</span><span class="p">)</span>
<span class="go">[[1 -- 3]</span>
<span class="go"> [-- 5 --]</span>
<span class="go"> [7 -- 9]]</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">x</span><span class="o">.</span><span class="n">compress</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">])</span>
<span class="go">masked_array(data = [1 3],</span>
<span class="go">      mask = [False False],</span>
<span class="go">      fill_value=999999)</span>
</pre></div>
</div>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">x</span><span class="o">.</span><span class="n">compress</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">],</span> <span class="n">axis</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="go">masked_array(data =</span>
<span class="go"> [[1 3]</span>
<span class="go"> [-- --]</span>
<span class="go"> [7 9]],</span>
<span class="go">      mask =</span>
<span class="go"> [[False False]</span>
<span class="go"> [ True  True]</span>
<span class="go"> [False False]],</span>
<span class="go">      fill_value=999999)</span>
</pre></div>
</div>
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